ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

CLEARCUT
LOGGING &
COMPLETE
BURN
DEER h
MOUSE
HERBACEOUS
GROWTH
GRASSES,
TREE SEEDLINGS,
& SAPLINGS,
BRUSH
RABBITS
PORCUPINE
MATURE TREES,
LESS HERBACEOUS
GROWTH
ONLY IN NATURA
SUCCESSION -
Figure 1.--SmZZ ma~mnaZs found in the successionaZ
stages after cZearcut logging and burning.
Deer mice (~erom~scus man&uZatus) are present in most stages of plant succession,
but not always in great numbers. They are a pioneering species that proliferate on
newly burned clearcuts soon after the ash has settled. Their diet at this time is
insects, conifer seeds, and other seeds that remain in the soil after burning. As the
vegetation develops, the seeds of herbaceous plants are eaten. Apparently the
nocturnal habits (LoBue and Darnel 1 1959) and erratic movements of these mice provide
some protection from predators. Deer mice are most abundant in clearcuts about five
years after logging, but decrease with time and vegetal development. Sometimes this
decrease is rapid. Numbers in closed-canopy forests are usually quite low.
Open areas are preferred by pocket gophers (~homom~s talpoides) and Columbian
ground squirrel s (~pemo~hCZus colwnbianus) . The protective burrow systems of these
animals enable them to invade and use large open areas that lack shrub or tree cover.
Opening of the forest canopy and coincident development of herbs results in optimum
habitat conditions.
Go1 den-mantl ed ground squirrel s (~~errno~hi~us
ZateraZis) and chipmunks (fitmias
spp. ) prefer open areas, but they are reluctant to venture where cover from boulders,
fallen trees, limbs, or shrubs is lacking. The numbers of these animals increases in
partial cuts and clearcuts where some residue remains on the ground (Davis 1976).